All files packer-sync.js

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"use strict";
 
let hasSyncZlib = true;
let zlib = require("zlib");
Iif (!zlib.deflateSync) {
  hasSyncZlib = false;
}
let constants = require("./constants");
let Packer = require("./packer");
 
module.exports = function (metaData, opt) {
  if (!hasSyncZlib) {
    throw new Error(
      "To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0"
    );
  }
 
  let options = opt || {};
 
  let packer = new Packer(options);
 
  let chunks = [];
 
  // Signature
  chunks.push(Buffer.from(constants.PNG_SIGNATURE));
 
  // Header
  chunks.push(packer.packIHDR(metaData.width, metaData.height));
 
  if (metaData.gamma) {
    chunks.push(packer.packGAMA(metaData.gamma));
  }
 
  let filteredData = packer.filterData(
    metaData.data,
    metaData.width,
    metaData.height
  );
 
  // compress it
  let compressedData = zlib.deflateSync(
    filteredData,
    packer.getDeflateOptions()
  );
  filteredData = null;
 
  if (!compressedData || !compressedData.length) {
    throw new Error("bad png - invalid compressed data response");
  }
  chunks.push(packer.packIDAT(compressedData));
 
  // End
  chunks.push(packer.packIEND());
 
  return Buffer.concat(chunks);
};